Apparatus for separating water and particulate material from flowing gases

ABSTRACT

An in-line dehydrating and particle removing apparatus for use in gas lines. The apparatus comprises a tubular body adapted to be connected into a gas flow line and including means responsive to the flow of gas therethrough for imparting a swirling or spiralling movement to the gas to cause the separation therefrom of liquid and finely divided solid particles by centrifugal action. Means is also provided for spraying a suitable liquid, such as a glycal, or the like, into the flowing gas in response to a reduction of pressure therein to absorb water from the gas and to coat finely divided particles in the gas to cause separation of the same by centrifugal action. The apparatus includes means responsive to the flow of gas therethrough for causing removal of the separated materials from the gasline and means for separating solid particles from the materials thus removed and returning the liquid portion thereof to the flowing gas for reuse in the separation of further water and particles.

Unite States Patent Vernon C. 11. Richardson 5312 Brae Burn, Houston,Tex. 827,330

May 23, 1969 Jan. 1 1, 1972 [72] lnventor [21] App]. No. [22] Filed [45Patented [54] APPARATUS FOR SEPARATING WATER AND PARTICULATE MATERIALFROM FLOWING 3,311,355 3/1967 Rait 3,345,046 10/1967 Versluysetal.

ABSTRACT: An in-line dehydrating and particle removing apparatus for usein gas lines. The apparatus comprises a tubular body adapted to beconnected into a gas flow line and including means responsive to theflow of gas therethrough for imparting a swirling or spiralling movementto the gas to cause the separation therefrom ofliquid and finely dividedsolid particles by centrifugal action. Means is also provided forspraying a suitable liquid, such as a glycal, or the like, into theflowing gas in response to a reduction ofpressure therein to absorbwater from the gas and to coat finely divided particles in the gas tocause separation of the same by centrifugal action. The apparatusincludes means responsive to the flow of gas therethrough for causingremoval of the separated materials from the gasline and means forseparating solid particles from the materials thus removed and returningthe liquid portion thereof to the flowing gas for reuse in theseparation of further water and particles.

PATENTEB JAN] 1 I972 A TTO/PN E Y BACKGROUND OF THE INVENTION In theproduction of gases from wells or other sources, such gases frequentlycontain water vapor, which at times may condense at various locations tointerfere with the proper functioning of equipment used in connectionwith the production and distribution of the gas. At times thetemperature of the gases may be greatly lowered by expansion to causethe formation of crystalline hydrates or ice which may build up oraccumulate in the flow line to an extent to interfere with the flow ofgas or the operation of equipment, such as valves, meters, or the like.

The reduction of the water content of the gas or complete removal of thesame has been attempted heretofore by various types of apparatus whichare subject to a number of serious disadvantages in that as heretoforecommonly constructed they cannot be readily applied to a gas flow linewithout substantial interference with the flow of gas. Some gas driersused for this purpose are also inefficient and require constantattention and maintenance, as well as being very expensive to build andoperate.

A further problem frequently encountered in the operation of gaslines isthe presence in the gas of finely divided solids, such as crystals ofsulfur, particles of dust or sand, talc, or the like, which cannot bereadily removed, but which may settle out or accumulate at locations tointerfere with the operation of the line.

Attempts have been made heretofore to remove water from flowing gaslinesby causing the gas to move circumferentially therein to remove the waterby centrifugal action. The effective removal of water in this manner issometimes unsatisfactory, especially under conditions in which the wateris in a vaporous state not readily separated by centrifugal force of themagnitude obtainable in a flow line of limited diameter. Moreover, veryfinely divided solids, such as those having a particle size below 404are not sufficiently affected by centrifugal action to be readilyremoved by apparatus of this kind.

SUMMARY OF THE INVENTION Briefly described, the gas treating apparatusof the present flow line without substantially interfering with the flowof gas therein and which imparts a swirling or spiralling motion to thegas to cause separation of water and solid particles by centrifugalaction, whereby such entrained materials are thrown against thesurrounding wall of the pipe. The apparatus includes means forintroducing a spray or mist of suitable hygroscopic material such asglycols, glycerin, or the like, into the gas during the swirling orspiralling of the same to absorb water vapor and deposit the same withthe absorbent material against the surrounding wall of the pipe.

The apparatus also includes means responsive to the flow of gas throughthe apparatus for causing a flow of fluid along the internal surface ofthe pipe to carry the absorbent material with the water and particles toa location to be removed from the line. The means for causing such flowcomprises an elongated chamber or outflow passageway located externallyof the flow way and having an inlet through which material may flow fromthe internal surface of the pipe into the chamber, and pressure reducingmeans disposed in the flow line in position to cause a reduction in thepressure in the chamber in response to the flow of gas in the line tocause the separated material to be drawn into the chamber. Means isprovided for removing the separated material from the chamber,separating solids therefrom and reintroducing the liquid into the flowline as a spray or mist, whereby the absorbent liquid may be recycledthrough the apparatus.

BRIEF DESCRIPTION OF THE VIEWS OF THE DRAWINGS FIG. I is a sideelevational view, partly in longitudinal, central cross section,iilustrating a preferred embodiment of the invention; and,

FIG. 2 is a fragmentary, longitudinal, cross-sectional view, on asomewhat enlarged scale, showing details of structure of the spraying ormisting nozzle of the apparatus.

DETAILED DESCRIPTION OF A PARTICULAR EMBODIMENT OF THE INVENTION Theapparatus of the invention comprises a tubular body 10, which mayconveniently take the form of a section of pipe of a size at least equalin internal diameter to that of the gasline into which the apparatus isto be connected and which may be provided at its ends with suitablemeans, such as the external flanges 12, by which the body may beconnected into the line.

Within the body 10 an internal flow pipe 14 is disposed, which is ofsomewhat smaller diameter than the body, and which is positioned inradially inwardly spaced relation to the internal surface of the body toform therewith an elongated, annular outflow chamber 16.

The flow pipe 14 is formed at its inlet end with an external outwardlyflared portion or mouth 18, through which gas may flow into the flowpipe and which closes the forward end of the chamber 16.

The downstream end of the flow pipe 14 is open and extends over theinlet end of an outlet fitting of bushing 20, in radially outwardlyspaced relation thereto to form an annular discharge passageway 22 intothe chamber 16. The fitting 20 is fitted into the downstream end of thebody 10 and has a bore 24 therethrough which tapers longitudinallyinwardly to provide an inner end wall portion 26 whose outside diameteris substantially smaller than the inside diameter of the downstream endof the flow pipe 14 into which the fitting is extended to form theannular passageway 22.

At its outer end the fitting 20 may have an outwardly flaring, bevelledend face 28.

Within the forward end of the flow pipe 14 inwardly of the mouth 18thereof, a spiral vane 30 is disposed, which may take the form of anelongated twisted platelike member, shaped to cause a swirling orspiralling movement of the gas flowing through the line. The spiral vane30 may, of course, be of any desired length and the turns thereof may beat any desired pitch and any number of such turns may be provided. Bythis arrangement, gas flowing through the apparatus is caused to move ina spiral or swirling path along the flow pipe to impart centrifugalforce thereto by which relatively heavy materials, such as water vaporor finely divided solids are thrown radially outwardly against the innersurface of the flow pipe to separate such materials from the gas.

For the purpose of introducing a mist or spray of suitable material,such as glycerine, glycals, water-absorbent material, or the like, intothe gas during the swirling movement of the same, a nozzle device,generally designated 32, is provided, which may be in the form of agenerally teardrop-shaped body positioned centrally in the flow pipewith its pointed end 34 directed upstream at or near the downstream endof the vane 30. The nozzle member 32 has an internal central cavity 36,from which a number of small discharge passageways 38 lead to theexterior at the downstream end of the nozzle and are directed somewhatradially outwardly to direct the spray into the gas toward thesurrounding wall of the flow pipe.

A liquid supply pipe 40 is connected to the nozzle 32 in communicationwith the cavity 36 thereof which leads from a collection receptacle ortank 41, from which the absorbent liquid is supplied to the nozzle.

The nozzle member 32 may be conveniently supported in the flow pipe byinserting the same in an end notch 42 formed in the downstream end ofthe vane 30 and securing the same in place in any convenient manner, asby welding or soldering.

One or more discharge pipes or nozzles 44 are disposed within theupstream end of the flow pipe 14, which preferably take the form ofsmall curved pipes or elbows tapering toward their outlet ends and incommunication at their inlet ends with the interior of the chamber 16.The nozzles 44 are directed downstream in the flow pipe, to cause areduction in the pressure in the chamber 16 during the flow of gasthrough the line, whereby the material deposited on the internal surfaceof the flow pipe will be drawn into the chamber through the annularpassageway 22 and be moved toward the forward end of the chamber.

The body has a side outlet pipe 46 which is in communication with theinterior of the chamber 16 mediate the ends of the chamber and whichleads downwardly therefrom into the reservoir or tank 41 to allow theoutflow of material from the chamber into the tank.

Within the tank 41 a funnellike receptacle 48 is located beneath theoutlet pipe 44 to receive solids which are deposited from the liquidcollected in the tank, and which is disposed to discharge the solidsfrom the tank through a discharge pipe 50, under the control of adischarge valve 52. The valve 52 may conveniently be of a type which isdiaphragm operated by diaphragm mechanism 54 of a conventional typehaving pressure fluid lines 56 and 58 in communication with the interiorof a diaphragm casing on opposite sides of a flexible diaphragmoperatively connected to the discharge valve.

The diaphragm mechanism is constructed to be supplied with pressurefluid for operation of the diaphragm through a supply pipe 60 from anysuitable source of fluid under pressure under the control of a floatvalve, generally designated 62, which is operated by a float 64 locatedin the tank 41.

By this arrangement a rise in the level of liquid in the tank causes thefloat valve to operate to open the discharge valve 52 to allow anoutflow of liquid from the tank through the pipe 50 carrying with itaccumulated sludge or solid particles from the receptacle 48 andlowering the liquid levelin the tank until the float valve is operatedto close the discharge valve.

In making use of the invention the apparatus is connected into a gasflow line and the tank 41 is partly filled with a hygroscopic liquidsuch as ethylene glycol, propylene glycol, or other such suitablewater-absorbing material.

With the apparatus thus applied, the flow of gas through the flow pipe14 causes the stream of gas to follow a swirling or spiral path, due tothe vane 30, whereby water vapor and finely divided solid particles arethrown by centrifugal action against the surrounding wall of the pipe.The reduction in pressure caused by the venturi effect of the body ofthe nozzle 32 and the increased velocity of the gas as it passes alongthe flow tube, results in the withdrawal of liquid from the tank 41through the pipe 40, which is sprayed into the flowing gas to absorbwater therefrom and to wet finely divided solid particles entrained inthe gas which are then thrown by centrifugal action against the wall ofthe pipe. Due to the wetting action of the liquid particles of solidmatter are prevented from bouncing away from the wall and are retainedthereon by the liquid.

The flow of gas through the flow pipe 14 also produces a reduction inthe pressure in the chamber 16 from which gas is drawn out through thenozzles 44 to cause the separated liquid passing along the inner surfaceof the flow pipe to be drawn into the chamber through the passageway 22.The separated liquid thus drawn off into the chamber then flows backalong the chamber and out through the pipe 46 into the tank 41.

Solid particles in the liquid may settle into the funnel 48 to bedischarged therefrom with excess liquid upon opening of the dischargevalve 52 when the float valve 62 is opened in response to a rise inliquid level in the tank.

The recovered liquid in the tank is recycled into the apparatus throughthe pipe 40.

in the event that the hygroscopic liquid employed becomes saturated withwater or absorbs water to an extent that it is no longer efficient, theliquid may be drawn off from the tank 41 and replaced with dehydratedliquid, or suitable means of a usual type, not shown, may beincorporated in the apparatus for removing excess water from the liquid.

It will thus be seen that the invention, constructed as described above,provides apparatus for the treatment of the flowing gas to remove waterand solid particles therefrom, which is efficient in operation, presentsno substantial interference to the flow of gas, and whose operation andmaintenance is economical.

Having thus clearly shown and described the invention, what is claimedas new and desired to secure by Letters Patent 1s:

1. ln apparatus for treating a flowing gas to remove therefrom water andfinely divided solids:

a. a tubular body adapted to be connected into a gas flow line;

b. an inner tubular member in the body having a portion spaced radiallyinwardly from the wall of the body to form a flow way through the memberand an annular chamber surrounding the flow way;

c. means forming an outlet from the flow way into said chamber adjacentone end of the chamber;

d. means in the flow way positioned for contact with the gas flowingthrough the flow way to impart a swirling movement to the gas to apply acentrifugal force to particles in the gas tending to move such particlesradially toward the surrounding wall of the member;

e. means responsive to the flow of gas through the flow way forintroducing into the gas a liquid capable of absorbing water from thegas; and, l

f. means responsive to the flow of gas through the flow way for causinga reduction in the pressure in said chamber to cause an outflow .of suchliquid together with the water absorbed thereby from the flow waythrough said outlet.

2. The gas-treating apparatus as claimed in claim 1, wherein said meansfor introducing said liquid into said gas includes i. nozzle meanspositioned in said flow way;

j. means forming a passageway through which fluid may flow from thechamber into the flow way through said nozzle means; and,

k. means in said flow way positioned for coaction with the gas flowingthrough the flow way to cause a reduction in pressure in the flow way ata location to cause an outflow of liquid into the flow way through saidnozzle means.

2. The gas-treating apparatus as claimed in claim 1, wherein said means for introducing said liquid into said gas includes i. nozzle means positioned in said flow way; j. means forming a passageway through which fluid may flow from the chamber into the flow way through said nozzle means; and, k. means in said flow way positioned for coaction with the gas flowing through the flow way to cause a reduction in pressure in the flow way at a location to cause an outflow of liquid into the flow way through said nozzle means. 